Am I talking about Monopoly?
People no longer buy Monopoly because of the gameplay. They buy it because of the theme. Either the theme evokes nostalgia, or looks pretty, or is associated with some brand that they like. The fun in playing the game has to do with the shape of the pieces, the familiarity of concepts on the board and cards. The game itself is always the same, and no one really cares about the game of Monopoly.
Or am I talking about war games?
Yikes. Now I'm entering dangerous territory. OK, I admit that there are more differences in game play between the thousands of war games than the thousands of versions of Monopoly. But.
Very simple games have barely any tactics or strategy, or none at all.
Better games have tight rulesets and constrained actions, giving them very specific types of strategies and tactics. A game of Chess is entirely different from a game of Go. Each has very narrow rules, and the game possibilities seem to flourish, not despite, but because of those rules. It's the same way that a sonnet with it's archaic and confined meter and rhyme result in poetry that is so much harder to achieve with free verse.
I have always admired "war games", but that is mostly because I have played so few of them. I admire them because they have so much strategy and so much tactics, the field is just wide open. But.
Update: A few hours after I posted this I realized that I am wrong. Or, probably wrong. What I wrote was like writing that all people of a certain culture all look alike. Once you get to know the culture, you realize how different they all are. This is probably true about war games as well. I am probably just looking in the wrong place. The things that I look for in games may not be different in each war game, but there may be all sorts of things that are.
If all strategy and tactics can be applied to game after game, then the same best strategy and tactics are going to apply to game after game. What you have, is the same game, with a changed name, graphics, shape of the playing pieces, and small changes to the rules here and there. And a different theme.
But wait a minute. Maybe I'm talking about video games!
There are only a few major types of video games: RTS, RTT, civ building, and so on. I've played even less video games than I've played war games, so I'm probably off my gourd here, but: does RTS equal Monopoly? Is every RTS game simply the same game with the pictures changed and a few changes to the rules? Do you play the next game because the game play is so different, or because of the shape of the pieces and the familiarity of concepts on the weapons list and enemy fighters?
And the more open and freeform the video game, the more likely that it will feel just like a previous game, if you 'close your eyes'. Been there, done that. The only thing new is the shapes and icons.
Update: And the same comment may also apply to video games. Comments, anyone?
It seems to me that the only way to get something different is to limit your game to having less strategic and tactical options. The game play is then about making the most of what you have, not about being the best you can be in a completely freeform environment.
That is pretty much where Eurogames fit in. Sure, there are way too many of those, too, and a whole lot of them feel like retreads of previous Eurogames, too. But there are a whole lot more categories of Eurogames, because Eurogame don't put the whole kit and caboodle into every game, just a few combinations thereof.
It's simple combinatorial theory, actually. If you choose 1 item out of 10, you have 10 choices. If you choose 2 items, you have 45 choices. 3 is 120, 4 is 210, 5 is 252, 6 is 210, 7 is 120, 8 is 45, and 9 is 10.
If there exist 10 tactical options in the entire world, every game with all 10 options is going to be exactly the same. There are only 10 games each of those with only 1 or 9 tactical options, and they will get old fast. Different and interesting games exist only in the 2 to 8 tactical option range.